Logarithms

Have you ever seen this: log10(1000) = 3 before?

That is called a logarithm. A logarithm is a mathematical way to take huge numbers and make them seem smaller and easier to work with. In the example, the logarithm of 1000 to base 10 is 3 (log10(1000) = 3), because 10 to the power of 3 is 1000: 103 = 1000. The Richter Scale (the measurement of earthquakes) and cryptography (secret code writing) use logarithms.

The birth of Logarithms can be attributed to John Napier, a Scotsman who some say was crazy. He also created the Napier Bones, an instrument used to easily calculate multiplication of large numbers.
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Napier's Bones


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Napier-example-1.png
If you wanted to multiply 46785399 x 7, you would line up your rods and then add the diagonals from right to left, carrying when need be.
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Though you would need some scratch paper, this is a quick way that someone can multiply two large numbers together.


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References:
"John Napier." Accessed from http://en.wikipedia.org/wiki/John_Napier
"Logarithm." Accessed from http://en.wikipedia.org/wiki/Logarithm
"Napier's Bones." Accessed from http://en.wikipedia.org/wiki/Napier%27s_bones